DC/DC converters are used in a very large number of applications. For example, DC/DC converters are used to provide a second DC voltage on the basis of a first DC voltage. For example, DC/DC converters are used where it appears to be more efficient to distribute a single DC voltage from an AC/DC converter across a circuit and to provide different DC voltages locally in the proximity of the consumers. Also, DC/DC converters are often used in battery powered devices to provide the supply voltage for the circuitry on the basis of the battery voltage, which may be different from the supply voltage of the circuitry and which may vary over time.
In many applications it is desirable to be able to adapt a DC/DC converter to strongly varying load conditions. For example, this is necessary if the circuitry supplied by the DC/DC converter can operate both in a high power mode and a low power mode or sleep mode, where the current consumption is close to zero but not equal to zero. Moreover, it has been recognized that the efficiency of a DC/DC converter should be as high as possible in both operating conditions, i.e. under both high load and low load.